Routine Checks Reveal Stress Cracks On 15 Aircraft

More aging US military aircraft are under investigation for
possible airframe fatigue issues. Inspections have been ordered for
all US Navy and Marine Corps F/A-18 Hornets after finding stress
cracks in aileron hinges on at least 15 planes.

Thursday's inspection bulletin affects F/A-18 A through D
models, with some 636 aircraft to be checked within their next 15
flight hours. Of those older "legacy" aircraft, 112 are actively
deployed, the Navy Times reported.

"Those aircraft that do not pass inspection criteria will be
grounded or flight restricted until failed material is replaced,"
said Navy spokesman Lt. Clay Doss, adding that so far none had been
grounded.

Earlier this month, during a routine post-flight maintenance
inspection of an F/A-18, a crack in an aileron hinge was
discovered, which led to inspections of Hornets from various
squadrons. When similar cracks were found on 14 other planes, a
fleetwide inspection bulletin was issued.

Doss said priority will be given to the 112 deployed aircraft to
reduce the impact on current missions. Inspections, which will
involve "nondestructive testing," are expected to be completed
within a two-week time frame.

Options include replacing the entire outer-wing panel or
replacing the hinge itself, Doss said. Replacing just the hinge
would require taking the aircraft to a repair depot, and if
necessary, the process of swapping out an outer-wing panel takes
about four days.

Boeing spokesman Philip Carder said, "Boeing will work closely
with the Navy throughout the inspection process to determine the
scope of any cracking on the F/A-18 A-D Hornet fleet and determine
the best course of action for repair. A more complete assessment of
the extent of this issue will be made after all inspections are
accomplished."

The F/A-18s under scrutiny reportedly have accumulated between
5,000 and 7,500 flight hours, which is still well within the
Hornet's twice-extended 10,000 hour maximum life span. But concerns
are arising about a gap between the expected retirement of the
older McDonnell-Douglas (now Boeing) F/A-18s and arrival of their
replacement, the Lockheed-Martin F-35C.

The deficit, which is forecast from 2015 to 2025, is likely to
be at its maximum in 2017, when the overall count is predicted to
be down by 69 aircraft.